Device For Superimposing Adjacent Sheets In A Conveying Line

ABSTRACT

A device is associated to an automatic enveloping machine for superimposing sheets or packets of sheets. In the device a first belt conveyor group receives one sheet packet of sheets from a conveying line located upstream and conveys the sheet or packet of sheets along a first path, first raising and then going down, toward an outlet station. A second belt conveyor group receives a second sheet or packet of sheets from the conveying line and conveys the sheet of packet of sheets along a second path, first going down and then raising, having the same length as the first path, toward the outlet station. At the outlet station the sheet or packet of sheets coming from the first path is placed over the sheet or packet of sheets coming from the second path, to define a package.

BACKGROUND OF INVENTION

The present invention relates to automatic machines for preparing and inserting packets of documents, advertising printed matters and similar into envelopes.

DESCRIPTION OF THE PRIOR ART

The above mentioned machines include a conveying line, onto which known devices, known to those skilled in the art as sheet feeders, deliver single documents, advertising printed matters or similar, in synchrony with the conveying line speed, so that they are placed in front of driving lugs, possibly on top of other sheets delivered by the previous sheet feeders.

The conveying line carries the packets to an enveloping station, in which suitable means introduce each packet into a related envelope.

In other machines, the packets in the enveloping station are wrapped continuously with a sheet of protective material, for example a plastic or paper material film; then, the film is welded and cut crosswise between one packet and another.

In both cases, the above mentioned machines have been conceived and manufactured so as to work at high speed, therefore all the working means must fulfill the requirements imposed by this condition.

The above mentioned machines must have a particular conformation, according to operation necessities.

In particular, the present invention satisfies the requirement of superimposing two sheets, which are situated one beside the other on the conveying line, and which have been obtained by, e.g. longitudinal cutting along the center line, made in a sheet delivered by a corresponding sheet feeder.

Likewise, there is the necessity for superimposing two packets of piled up sheets, which have been obtained by a longitudinal cut performed along the center line of a pile of sheets, formed by subsequent deliveries of a plurality of sheet feeders, arranged in a series.

SUMMARY OF THE INVENTION

The object of the present invention is to propose a device for superimposition of adjacent sheets, structured in such a way that it can be associated to the conveying line of a related automatic machine for preparing and enveloping packets, being suitable to work correctly also at the machine maximum operation speed.

Another object of the present invention is to propose a device aimed at superimposing, without distinction, two single sheets or two packets of piled up sheets, maintaining the same operation reliability.

A further object of the present invention is to propose a device, which is capable of performing an extremely precise superimposition of two sheets or of two packets of sheets, in particular considering the alignment of the two respective front edges.

The above mentioned objects are obtained in accordance with the contents of the claims by a device for superimposing adjacent sheets or packets of sheets in a conveying line, the line being part of an automatic machine for preparation and enveloping of packages formed by two superimposed sheets or by two superimposed packets of sheets, said device including:

a first belt conveyor group for receiving a first sheet or packet of sheets from said conveying line and for conveying said first sheet or packet of sheets along a prefixed first path, first raising and then going down, and toward an outlet station, to define an upper sheet or an upper packet of sheets of said package being formed; a second belt conveyor group for receiving a second sheet or packet of sheets from the same conveying line and for conveying said second sheet or packet of sheets along a prefixed second path, first going down and then raising, toward said outlet station, to define a lower sheet or lower packet of sheets of said package being formed, with said belt conveyor groups determining longitudinal alignment of front edges of said sheets or packets of sheets, at said outlet station.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristic features of the invention will be pointed out in the following description of a preferred embodiment of the proposed device, in accordance with the contents of the claims and with reference to the enclosed figures, in which:

FIG. 1 is a schematic, perspective view of the main steps performed for the superimposition of two sheets;

FIG. 2 is a top view of what shown in FIG. 1; FIG. 3 is a lateral, schematic view of the device;

FIG. 3A is a schematic, lateral view of a first group of the device, acting on the sheet aimed at being placed over another one;

FIG. 3B is a schematic, lateral view of a second group of the device, acting on the sheet aimed at being placed under another one.

DISCLOSURE OF THE PREFERRED EMBODIMENT

Having regards to the above Figures, the reference numeral 1 generally indicates the proposed device.

The device 1 is situated downstream of a conveying line (not shown in detail), which is part of a known automatic machine for preparing and enveloping the packets, likewise not shown.

Two sheets 11, 12, arranged one beside the other and obtained for example by longitudinal cutting along the center line of a sheet 10 delivered upstream, by a corresponding sheet feeder of known type, not shown, are moved forward along the conveying line, toward the device 1.

The device 1 is aimed at superimposing the two sheets 11, 12, so as to form a package P, which is to be enveloped.

Likewise, the device 1 is aimed at preparing a package PI, formed by superimposing two packets of piled up sheets 110, 120, obtained by longitudinal cutting along the center line of a pile of sheets 100, which has been obtained by subsequent deliveries of single sheets 10 by a plurality of sheet feeders arranged in series.

The device 1 includes two belt conveyor groups 21, 22, first and second, aimed respectively at acting on one and on the other of the sheets 11, 12 or packets of sheets 110, 120.

Each of the first and second conveying groups 21, 22 includes a pair of endless belts, respectively upper belts 31, 32 and lower belts 41, 42, mounted on relevant pulleys 51A, 51B, 52A, 52B, 61A, 61B, 62A, 62B, each one having horizontal axis.

The upper belt 31, 32 of each group faces the related lower belt 41, 42, so as to define a corresponding central operating run R1, R2.

The belts of each pair are counter-rotated with equal speed V, so that the relative speed of the belts along the operating runs R1, R2 is zero.

Obviously, the sheets 11, 12 or packets of sheets 110, 120 are carried by the conveying line with the same speed V.

The respective initial parts 21 a, 22 a of the conveyor groups 21, 22, situated upstream, are arranged one beside the other at a prefixed distance, and are disposed in such a way as to lye each one substantially in the center of the respective sheet 11, 12 or packet of sheets 110, 120, coming from the conveying line.

The operating run R1 of the first conveyor group 21 extends from its initial part 21 a to define a prefixed first path T1, first rising and then going down, while the second operating run R2 of the second group 22 extends likewise from its initial part 22 a to define a prefixed second path T2, first going down and then rising.

The development of the paths T1, T2 allows the two groups to be convergent, with respect to a horizontal plane, toward an outlet station SU, in which the terminal part 21 b of the first group 21 is placed over the terminal part 22 b of the second group 22 (FIGS. 1 and 2).

Consequently, the sheet 11 or the packet of sheets 110, carried by the first group 21 goes to form the upper part of said package P, PI, while the other sheet 12 or packet of sheets 120 forms the lower part thereof

The total length of the two paths T1, T2 is identical, so as to assure a precise longitudinal alignment of the two front edges 11 a, 12 a, 110 a, 120 a of the sheets 11, 12 or of the packets of sheets 110, 120 during the formation of the package P, PI.

The return pulley 51A of the upper belt 31 of the first group 21, upstream with respect to the conveying line, is aligned with the corresponding pulley 52A of the upper belt 32 of the second group 22, while the upstream return pulley 61A of the lower belt 41 of the same first group 21 is aligned with the corresponding pulley 62A of the lower belt 42 of the second group 22 (FIG. 3).

The above mentioned upstream return pulleys 51A, 52A of the upper belts 31, 32 are suitably set back with respect to the corresponding pulleys 61A, 62A of the lower belts 41, 42 (FIG. 3), so as to anticipate the gripping of the sheets 11, 12 or of the packets of sheets 110, 120, when they are still placed on the conveying line.

The alignment of the pulleys 51, 52 ensures the simultaneous gripping of in the two groups.

The return pulley 61B of the related lower belt 41 of the first conveyor group 21, downstream of the outlet station SU, is set back with respect to the corresponding return pulley 51B of the upper belt 31 (FIGS. 3 and 3A).

On the contrary, the return pulley 62B of the related lower belt 42 of the second conveyor group 22 is situated downstream of the outlet station SU and is in a forward offset position with respect to the corresponding return pulley 52B of the upper belt 32 (FIGS. 3 and 3B).

The combination of these two features allows to bring the two overlapping terminal parts 21 b, 22 b of the groups 21, 22 as close to each other as possible, so as to guide the superimposition of the sheets 11, 12 or packets of sheets 110, 120 in the best way possible.

According to a preferred constructive solution, the first path T1 and the second path T2 define, by deflecting rolls, not shown, consecutive portions of the operating runs R1, R2, having different inclination with respect to each other and aimed at increasing the contact pressure between the relative opposite belts and, consequently, the gripping action performed thereby on the respective sheet 11, 12 or the packet of sheets 110, 120.

This solution is particularly advantageous for the good operation of the device 1 when each group acts on only one sheet 11, 12, to avoid slipping and consequently shifting of a sheet carried by one group with respect to the other, for instance caused by an insufficient gripping, as well as when one packet of sheets 110, 120 is acted on, so as to avoid the misalignment of the intermediate sheets of the packet, caused by an insufficient gripping.

Therefore, as it is easily deduced from the above description, the device 1 receives the two sheets 11, 12 or the packets of sheets 110, 120 carried by the conveying line and brings them, maintaining their forward movement speed V, to be arranged one over the other, with the relative front edges 11 a, 12 a, 110 a, 120 a perfectly aligned, to form a package P, PI, in such a way that the latter can take, from the outlet station SU, a conveying line L (FIG. 2), which transfers it to an enveloping station (not shown) of the machine.

The optimal operation of the device is ensured also at high operation speed, with which the machines can operate, by the fact that the convergence angle between the two groups is intentionally very limited, therefore the entity of the deviation of the sheets from the direction imposed by the conveying line, when they enter the device, is negligible.

The positive characteristics of the proposed device, appeared from what has been said so far, allow to reach the expected objects by a simple and reliable solution of a limited cost.

It is important to highlight the versatility of the device, which is aimed at superimposing, without distinction, two single sheets or two packets of piled up sheets, maintaining the same working reliability and assuring, at the same time, the same alignment precision of the front edges.

It is understood that what above is a mere, not limiting example. Therefore, it is obvious that any detail changes remain within the protective scope defined by the following claims. 

1. A device for superimposing adjacent sheets or packets of sheets in a conveying line, the line being part of an automatic machine for preparation and enveloping of packages formed by two superimposed sheets or by two superimposed packets of sheets, said device including: a first belt conveyor group for receiving a first sheet or packet of sheets from said conveying line and for conveying said first sheet or packet of sheets along a prefixed first path, first raising and then going down, and toward an outlet station, to define an upper sheet or an upper packet of sheets of said package being formed; a second belt conveyor group for receiving a second sheet or packet of sheets from the same conveying line and for conveying said second sheet or packet of sheets along a prefixed second path, first going down and then raising, toward said outlet station, to define a lower sheet or lower packet of sheets of said package being formed, with said belt conveyor groups determining longitudinal alignment of front edges of said sheets or packets of sheets, at said outlet station
 2. A device, according to claim 1, wherein each of said first and second conveyor groups includes a pair of endless belts, respectively an upper endless belt and a lower endless belt, mounted on relevant pulleys having horizontal axis, the endless belts of each pair of endless belts being operated so as to counter-rotate with equal speed, with the upper endless belt of each group of endless belts facing a relevant lower endless belt to define a corresponding first operating run extending along said first path, and a second operating run extending along said second oath.
 3. A device, according to claim 1, wherein a downstream return pulley of said lower endless belt of said first belt conveyor group is set back with respect to a corresponding return pulley of said upper endless belt.
 4. A device, according to claim 1, wherein a downstream return pulley of said lower endless belt of said second belt conveyor group is offset to an advanced position with respect to a corresponding return pulley of the upper endless belt.
 5. A device, according to claim 1, wherein said first path includes consecutive portions of said first operating run having different inclination for increasing contact pressure between related opposite belt conveyors of said first belt conveyor group, consequently, gripping action performed on the sheet or packet of sheets.
 6. A device, according to claim 1, wherein said second path includes consecutive portions of said second operating run having different inclination for increasing contact pressure between related opposite belt conveyors of said second belt conveyor group, consequently, gripping action performed on the sheet or packet of sheets.
 7. A device, according to claim 1, wherein said first and second paths have equal length.
 8. A device, according to claim 2, wherein an upstream return pulley of the upper endless belt of the first belt conveyor group is aligned with a corresponding upstream return pulley of the upper endless belt of the second belt conveyor group, and an upstream return pulley of the lower endless belt of the first belt conveyor group is aligned with a corresponding upstream pulley of the lower endless belt of the second belt conveyor group, whereas said upstream return pulleys of the upper endless belts are set back with respect to corresponding return pulleys of the lower endless belts.
 9. A device, according to claim 2, wherein a downstream return pulley of said lower endless belt of said first belt conveyor group is set back with respect to a corresponding return pulley of said upper endless belt.
 10. A device, according to claim 2, wherein a downstream return pulley of said lower endless belt of said second belt conveyor group is offset to an advanced position with respect to a corresponding return pulley of the upper endless belt.
 11. A device, according to claim 2, wherein said first path includes consecutive portions of said first operating run having different inclination for increasing contact pressure between related opposite belt conveyors of said first belt conveyor group, consequently, gripping action performed on the sheet or packet of sheets.
 12. A device, according to claim 2, wherein said second path includes consecutive portions of said second operating run having different inclination for increasing contact pressure between related opposite belt conveyors of said second belt conveyor group, consequently, gripping action performed on the sheet or packet of sheets.
 13. A device, according to claim 2, wherein said first and second paths have equal length. 